In a bank which treats a large number of banknotes, a machine to automatically perform decision processing of banknotes (such as counting the banknotes) is utilized. In this apparatus, for example, as to banknotes to be circulated in a market, a predetermined number (such as one hundred sheets) of banknotes are strapped by a strapping material as one bundle of banknotes. Furthermore, a predetermined number of bundles of banknotes are bundled by a bundling material as one group of bundles (each bundle including banknotes). The group of bundles (of banknotes) is packaged by a vinyl and so on. As a result, the large number of banknotes is managed.
Conventionally, in order to confirm whether the packaged group of bundles (of banknotes) include a suitable number of banknotes, technique to detect the number of banknotes by using an optical detection device (such as a camera) is known. However, in this conventional technique, there are cases that accuracy to detect the number of banknotes is not sufficient.